Laser ions holmium

Johnson et al. (55) observed energy transfer from erbium to thulium and from erbium to holmium ions in crystals. They were able to obtain substantial decreases in laser thresholds because of this energy migration. The fluorescent lifetime of the 3//4 state of thulium in CaMo04 containing 0.75 atomic per cent erbium and 0.5 atomic per cent thulium as inferred from the time delay before the onset of laser oscillation is 900 /xsec at both IT and 20°K. 

Possible sensitizers for lanthanide and actinide ions include other lanthanide and actinide ions, other transition group ions, and molecular complexes. These may be present either as added impurities or as a component of the host. Of the many sensitization schemes reported, some offer only marginal improvement. The most efficient crystal laser is "alphabet" holmium Ho3+ sensitized by Er +, Tm3+, and Yb +... 

The commercially important samarium-containing minerals are treated with concentrated sulfuric acid or, in the case of monazite, with a solution of sodium hydroxide (73%) at approximately 40°C (104°E) and under pressure. The element is separated from the solutions via solvent extraction or ion exchange. Sm salts are weakly yellow and may exhibit ion emission. Sm ions show luminescence and are sometimes used to generate lasers. Samarium is used in the manufacture of headphones and tape drivers, see ALSO Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Lutetium Neodymium Praseodymium Promethium Terbium Ytterbium. 

Specific examples of semiconductor laser array pumps include devices made from the AlGaAs material system. The emission wavelength can be varied from 700 to 900 nm by varying the Ga/Al composition. These emission wavelengths can be made to coincide with absorption bands of several important solid state lasing ions, such as neodymium, chromium, holmium, erbium, and promithium. 

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